The Kullu valley has two distinct visitor seasons. April to June is high summer: warm, dry, and crowded with Indian holidaymakers escaping the plains heat. Apple blossom in late April is one of the most beautiful sights in the valley.
September to November is the second peak, with clear days, cool nights, and the harvest in full swing. The Kullu Dussehra falls in October — book accommodation weeks ahead if you want to be in town for it. December to February is cold but quiet, with snow on the higher slopes. Monsoon (July, August) is best avoided: landslides on the roads from Mandi and Manali are a near certainty.